Be aware that both systems fail for
the very same reason, i.e. that tables aren't
files.

Information in relational database tables
often does not make sense unless it is taken together with
information in other tables with complex joins and search
conditions.

Ancient hierarchical databases could
have this one-to-one similarity, but they failed because
searching through them was only available in predefined
directions, while relational DBMS systems allow greater
flexibility.

Even if you find a way of reducing
complex queries to a simple file interface, so that I can
see a financial report as a file and edit it with Vi, such
interface would need to have several well written queries
in the background, and this leaves us with the same dilemma
we had with hierarchical databases, i.e. without a
pre-defined path, we can't have an answer to our
questions.

I'd rather write my own queries in Vim and use
a sensible script
to fetch the results.

I also think that KISS principle is best. So, as noted before, this module doesn't try to export complex relations in database. User have to create queries to export just part of database in which he or she is interested (good example included in distribution is WebGUI script which exports just templates). It's very much like vim script that you refer to (which is very useful if you just want to edit data using vim, ++ for that).

But, having part of database as filesystem allows you to use all filesystem utilities like grep, cp (rm and mv are not supported at the moment) as well as different editors, ftp or http servers and so on. You can even create tar of your data before you start to edit it, just as backup.